objtool: Add abstraction for destination offsets

The jump and call destination relocation offsets are x86-specific.
Abstract them by calling arch-specific implementations.

[ jthierry: Remove superfluous comment; replace other addend offsets
with arch_dest_rela_offset() ]

Signed-off-by: Raphael Gault <[e-mail]>
Signed-off-by: Julien Thierry <[e-mail]>
Acked-by: Peter Zijlstra (Intel) <[e-mail]>
Reviewed-by: Miroslav Benes <[e-mail]>
Signed-off-by: Josh Poimboeuf <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

tools/objtool/arch.h

···
 	struct op_src src;
 };
 
+struct instruction;
+
 void arch_initial_func_cfi_state(struct cfi_state *state);
 
 int arch_decode_instruction(struct elf *elf, struct section *sec,
···
 			    unsigned long *immediate, struct stack_op *op);
 
 bool arch_callee_saved_reg(unsigned char reg);
+
+unsigned long arch_jump_destination(struct instruction *insn);
+
+unsigned long arch_dest_rela_offset(int addend);
 
 #endif /* _ARCH_H */

tools/objtool/arch/x86/decode.c

···
 #include "../../../arch/x86/lib/inat.c"
 #include "../../../arch/x86/lib/insn.c"
 
+#include "../../check.h"
 #include "../../elf.h"
 #include "../../arch.h"
 #include "../../warn.h"
···
 	default:
 		return false;
 	}
+}
+
+unsigned long arch_dest_rela_offset(int addend)
+{
+	return addend + 4;
+}
+
+unsigned long arch_jump_destination(struct instruction *insn)
+{
+	return insn->offset + insn->len + insn->immediate;
 }
 
 int arch_decode_instruction(struct elf *elf, struct section *sec,

tools/objtool/check.c

···
 					       insn->offset, insn->len);
 		if (!rela) {
 			dest_sec = insn->sec;
-			dest_off = insn->offset + insn->len + insn->immediate;
+			dest_off = arch_jump_destination(insn);
 		} else if (rela->sym->type == STT_SECTION) {
 			dest_sec = rela->sym->sec;
-			dest_off = rela->addend + 4;
+			dest_off = arch_dest_rela_offset(rela->addend);
 		} else if (rela->sym->sec->idx) {
 			dest_sec = rela->sym->sec;
-			dest_off = rela->sym->sym.st_value + rela->addend + 4;
+			dest_off = rela->sym->sym.st_value +
+				   arch_dest_rela_offset(rela->addend);
 		} else if (strstr(rela->sym->name, "_indirect_thunk_")) {
 			/*
 			 * Retpoline jumps are really dynamic jumps in
···
 		rela = find_rela_by_dest_range(file->elf, insn->sec,
 					       insn->offset, insn->len);
 		if (!rela) {
-			dest_off = insn->offset + insn->len + insn->immediate;
+			dest_off = arch_jump_destination(insn);
 			insn->call_dest = find_func_by_offset(insn->sec, dest_off);
 			if (!insn->call_dest)
 				insn->call_dest = find_symbol_by_offset(insn->sec, dest_off);
···
 			}
 
 		} else if (rela->sym->type == STT_SECTION) {
+			dest_off = arch_dest_rela_offset(rela->addend);
 			insn->call_dest = find_func_by_offset(rela->sym->sec,
-							      rela->addend+4);
+							      dest_off);
 			if (!insn->call_dest) {
-				WARN_FUNC("can't find call dest symbol at %s+0x%x",
+				WARN_FUNC("can't find call dest symbol at %s+0x%lx",
 					  insn->sec, insn->offset,
 					  rela->sym->sec->name,
-					  rela->addend + 4);
+					  dest_off);
 				return -1;
 			}
 		} else
···
 		if (!insn->immediate)
 			continue;
 
-		dest_off = insn->offset + insn->len + insn->immediate;
+		dest_off = arch_jump_destination(insn);
 		if (dest_off == special_alt->new_off + special_alt->new_len) {
 			if (!fake_jump) {
 				WARN("%s: alternative jump to end of section",